Measuring device.



No. 886,106. PATENTED APR. 28,1908.

E. G. ADAMS.

MEASURING DEVICE.

APPLICATION FILED 001219, 1906.

1H5 mums PETERS co., \wlsHlNcrcN. b. c

iirrn EARL O. ADAMS, OF ALLEGHENY, PENNSYLVANIA.-

MEASURING- DEVIGE Specification of Letters Patent.

Patented April 28, 1908.

Application filed October 19, 1906. Serial No. 339,641.

To all whom it may concern:

Be it known that I, EARL O. ADAMs, a citi- Zen of the United States ofAmerica, residing at Allegheny, in the county of Allegheny,

, and State of Pennsylvania, have invented certain new and usefulImprovements in Measuring Devices, of which the following is aspecification, reference being had therein to the accompanying drawing.

This invention relates to measuring instruments, and more particularlyto that class of devices known as center finders, especially adapted forascertaining with accuracy the diameter of tubes or other cylindricalbodies.

The invention comprises a center-finder consisting of longitudinallyadjustable sections provided with graduations and spring mechanism forcontrolling the telescopic movement of the sections.

The invention also comprises certain detail features of construction andcombinations of parts all of which will be fully described hereinafterin connection with the accompanying drawing, which forms a part of thiss eciiication and defined in the appended c aims. Y

In the drawing, Figure 1 is a view in perspective of a center finderconstructed in accord ance with my invention, Fig. 2 is a frontelevation of the same applied to the interior of a tube, Fig. 3 is aside elevation of the device,

and Fig. 4 is a longitudinal section of the same.

The reference numerals 1 and 2 designatetwo overlapping bars, preferablyof rectangular form in cross section, to the outer end of each of whichis secured a bifurcated head 3 by means of screws 4 or like securingmeans. Each of the heads 3 .is recessed on its outer face to receive theends of the bars as indicated at 5, and the bar 1 is offset at 6adjacent to its outer end to bring said bar into parallel relation withthe bar 2. The ends 7 of the forks or arms of the heads 3 are beveled asshown, and the extremity of each of said arms is recessed to providelugs 8 adapted to engage the end of a tube as illustrated in Fig. 2.

The inner end of the arm 1 is provided with parallel plates 9 projectingfrom the o posite edges of the arm, and having opposite ly projectingflanges 1O overlapping the outer face of the bar 2 to serve as a guideto maintain the bars 1 and 2 in proper relation in their telescopicmovement.

The front face of the bar 2 is provided with graduate marks 11 theflanges 10 also having graduate marks extending from end to end of theflanges, the central or middle graduate mark on each flange beingindicated by the reference numeral 12. It will be understood of coursethat the bar 2 may be pro vided with a greater number of graduate marks,so as to give a Wider range to the use of the instrument, though theamount of graduate marks shown on the bar 2 is generally suflicient forall ordinary use of the device.

As shown in Fig. 2 of the drawings, the center of the pipe is found tobe exactly at the point indicated by the graduate marks 12 on theflanges 10. Assuming, however, that the device is placed in a pipe ahalf inch smaller in diameter than the one shown, the end graduation xon the bar 2 will then have been moved to the end y of the flanges 10;the distance from the ends y of the flanges 10 to the graduation marks12 is exactly onehalf inch. To determine the center, the graduate marksbetween the ends y of the flanges 10, and the end graduation a: arecounted, the number thereof divided by 2, and consequently the center ofthe pipe will be a quarter of an inch to the right of the graduate mark12, and a quarter of an inch to the left of the ends y of the flanges10. Again, it will be observed that if the graduate mark a: on the bar 2was moved to the graduate mark to on the flanges 10, the graduationsbetween graduate mark at of the bar 2 and the graduate marks 12 of theflanges, are counted, and the amount divided by 2, in which instance thegraduate mark a would indicate the center.

Secured to the rear face of each of the heads 3 by the screw 4 whichsecure the bars 1 and 2 to the heads, is a perforated bracket 13, thesebrackets serving as bearings for a sectional telescopic guide rodcomprising a tubular section 14, and a rod 15. Within the tube 14 is acoil spring 16 bearing at one end against a plug 17 fitted within theouter end of the tube 14 and at its opposite end against a shoulder 18formed on the rod 15 by circumferentially reducing the inner end of saidrod to provide a stem 19 which projects into the adjacent end of thecoil spring.

The utility and operation of the improvement constructed as thusdescribed will be readily understood. The device is placed within theend ofthe tube to be measured,

and the lugs 8 engage the edge of the tube as shown in Fig. 2.

It will be apparent that the tendency of the spring 16 is to force thetelescopic sections apart and hence after the arms 1 and 2 are forcedtogether against the tension of the spring, the expansion of said springwill clamp the heads 3 against the inner walls of the tube. Thus thedevice is adapted for use with tubes or other cylindrical bodies ofvarious sizes.

Instead of employing the tube 14 closed by a plug 17, the tube may beformed by boring out a solid rod leaving the outer end closed. Otherchanges in the details of the device may be resorted to which do notinvolve a departure from the terms and scope of the claims.

What I claim and desire to secure by Letters Patent, is

1. In a centering device, two overlapping bars, flanges carried by onebar and receiving the overlapping portion of the other bar and providedwith an indicating mark, the other of said bars being provided on itsouter face with graduations, heads carried by the outer ends of thebars, and means suspended from the heads and including a spring exertingits tension to normally force the heads away from each other.

2. A center-finder comprising two telescopic bars of equal length, onebearing gradnations on its outer face, while the other bar bears anindicating mark, heads secured to the outer ends of said bars, and asectional spring pressed guide secured to said heads.

3. A center-finder, comprising two telehaving flanged plates serving asa guide for the other bar, bifurcated heads secured to the outer ends ofsaid bars, and having their ends formed with lugs, brackets secured tosaid heads, and a telescopic guide supported by said brackets andcomprising a tube, a rod extending withinthe tube, and a coil springwithin said tube.

In testimony whereof I aflix my signature in the presence of twowitnesses.

EARL O. ADAMS. Witnesses:

H. C. EVERT, MAX H. SRoLovITz.

